Joint effects of cigarette smoking and irradiation in pregnant mice and their offspring.

BACKGROUND We have previously reported that irradiation of mice in utero significantly increased the tumor incidence in the offspring of irradiated mothers. The joint effects of irradiation and cigarette smoking (CS) on tumor incidence and on the process of carcinogenesis were investigated. MATERIALS AND METHODS Pregnant C57Bl/6J female mice were irradiated with a single dose of gamma-ray (1 Gy or 3 Gy) and/or exposed to CS of IR3 non-filtered cigarettes before or during pregnancy, tumors were investigated both with histological and immunohistochemical methods. RESULTS Longer exposure (60 days) of the mice to CS before pregnancy and irradiation during pregnancy significantly increased the tumor incidence in the mothers and their offspring. Parallel activation of Caspase-8 and inactivation of Caspase-9 was found. CONCLUSION Joint exposure of mice to prolonged CS before pregnancy and irradiation during pregnancy significantly increased the tumor incidence both in the mothers and their offspring.